Hello I understand this is an old post.
2004 Yukon XL 1500, auto climate control.
But I am fighting similar issues. Rear ac blows very cold. Front, more so drivers side, vents blow just air it seems while in ideal. Once I begin to drive, they blow "cooler" air, you can tell the ac is trying.. but the passenger side seems to be just a bit cooler. It seems I can only get the front to blow cooler air when the rear is on. I've turned it off just to see what the front does, seems to stay decently cool. Slowing down it gets warmer again.
Driver side use to be screaming hot! So I replaced the temperature mode actuator, the one closest to the floor towards middle. Once that was replaced, no more super hot air. I've also removed it and open and closed it manually and it still seems hot air is mixing with the cold.
Haven't done anything with the condenser or the evaporator.
Both hard to get to. Haven't replaced the other 2 actuators.
And the accumulator is obviously working properly.
I've replaced the climate control module, unfortunately it's not an OEM.. apparently those are hard to come by. But it seems to work. The factory one was glitching bad! I've done the pull fuse, let sit, let recalibrate/relearn several times. It honestly seemed to work a little. I've checked the freon levels, doesn't need anymore.
Helps is much appreciated.